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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

(Mark One)

OR

Commission file number: 1-10864

UNITEDHEALTH GROUP INCORPORATED

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (952) 936-1300

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act: NONE

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.    Yes  ¨    No  x

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.    Yes  ¨    No  x

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes  x    No  ¨

Indicate by checkmark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.  ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, or a non-accelerated filer. See definition of “accelerated filer and large accelerated filer” in Rule 12b-2 of the Exchange Act. (Check one):

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes  ¨    No  x

The aggregate market value of voting stock held by non-affiliates of the registrant as of June 30, 2006, was approximately $55,976,249,541 (based on the last reported sale price of $44.78 per share on June 30, 2006, on the New York Stock Exchange).*

As of February 15, 2007, there were 1,354,320,209 shares of the registrant’s Common Stock, $.01 par value per share, issued and outstanding.

Note that in Part III of this report on Form 10-K, we “incorporate by reference” certain information from our Definitive Proxy Statement for the Annual Meeting of Shareholders to be held on May 29, 2007. This document will be filed with the Securities and Exchange Commission (SEC) within the time period permitted by the SEC. The SEC allows us to disclose important information by referring to it in that manner. Please refer to such information.

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EXPLANATORY NOTE

In this Form 10-K, UnitedHealth Group Incorporated (“UnitedHealth Group” or the “Company”) is restating its Consolidated Balance Sheet as of December 31, 2005, and the related Consolidated Statements of Operations, Changes in Shareholders’ Equity and Cash Flows for each of the fiscal years ended December 31, 2005 and December 31, 2004 and quarterly financial data for the quarter ended December 31, 2005.

This Form 10-K also reflects the restatement of “Selected Financial Data” in Item 6 for the fiscal years ended December 31, 2005, 2004, 2003 and 2002, and the amendment of “Management’s Discussion and Analysis of Financial Condition and Results of Operations” presented in the Company’s Form 10-K for the fiscal year ended December 31, 2005 as it related to the fiscal years ended December 31, 2005 and December 31, 2004.

Immediately prior to the filing of this Form 10-K, the Company filed an amended quarterly report on Form 10-Q/A for the quarter ended March 31, 2006 and quarterly reports on Form 10-Q for the quarters ended June 30, 2006 and September 30, 2006. These Forms 10-Q/A and 10-Q contain restated financial information for the first three fiscal quarters of 2005 and the quarter ended March 31, 2006.

Previously filed annual reports on Form 10-K and quarterly reports on Form 10-Q (other than for the quarter ended March 31, 2006, which has been amended by the Form 10-Q/A) have not been amended and should not be relied upon.

Background of the Restatement

In March 2006, media reports questioned whether a number of companies, including UnitedHealth Group, had engaged in backdating stock option grants. Shortly thereafter, the Company was notified that the Securities and Exchange Commission (the “SEC”) had commenced an inquiry into the Company’s historic practices concerning stock option grants.

On April 4, 2006, the Company’s Board of Directors (the “Board”) created an independent committee comprised of three independent directors to review the Company’s option grant practices over the period from 1994 through 2005 (the “Independent Review Period”). The independent committee engaged the law firm of Wilmer Cutler Pickering Hale and Dorr LLP (“WilmerHale”) as counsel for its independent review, and WilmerHale retained independent accounting advisors. WilmerHale has advised that, in the course of its review, it examined physical and electronic documents comprising more than 26 million pages of material and conducted over 80 interviews.

WilmerHale’s report of its findings (the “WilmerHale Report”) was furnished to the Board and publicly issued on October 15, 2006. The complete text of the WilmerHale Report is available on the Company’s Web site, www.unitedhealthgroup.com, and is included as an exhibit to the Company’s Current Report on Form 8-K filed with the SEC on October 16, 2006.

After substantially completing its analysis of the accounting adjustments necessary to reflect the findings of the WilmerHale Report, on November 8, 2006, the Company filed with the SEC a Current Report on Form 8-K reporting management’s conclusion, which the Audit Committee of the Board had approved, that — due solely to the Company’s historic stock option practices — the Company’s financial statements for the fiscal years ended December 31, 1994 through 2005, the interim periods contained therein, the quarter ended March 31, 2006 and all earnings and press releases, including for the quarters ended June 30, 2006 and September 30, 2006, and similar communications issued by the Company for such periods, and the related reports of the Company’s independent registered public accounting firm, should no longer be relied upon. The Form 8-K also reported that management had re-evaluated its assessment of the Company’s internal controls over financial reporting and had concluded that, as of December 31, 2005, the Company had a material weakness solely relating to stock option plan administration and accounting for and disclosure of stock option grants.

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The Form 8-K also disclosed that certain of the Company’s current and former senior executives had agreed to increase the exercise price of all stock options granted to that executive with stated grant dates between 1994 and 2002 to eliminate any financial benefit resulting from what the WilmerHale Report concluded was the likely backdating of grants that they received.

After completing its internal review of the accounting treatment for all option grants, and following consultation on certain interpretive accounting issues with the Office of the Chief Accountant of the SEC, management has concluded, and the Audit Committee of the Board has approved the conclusion, that the Company used incorrect measurement dates and made other errors described below in accounting for stock option grants and, accordingly, that the Company’s previously issued financial statements should be restated in this Form 10-K.

Summary of the Restatement Adjustments

As of January 1, 2006, the Company adopted Statement of Financial Accounting Standards No. 123 (revised 2004), “Share-Based Payment” (FAS 123R), using the modified retrospective transition method. Under this method, all prior period financial statements are required to be restated to recognize compensation cost in the amounts historically disclosed in our consolidated financial statements under Statement of Financial Accounting Standards No. 123, “Accounting for Stock-Based Compensation” (FAS 123). Prior to January 1, 2006, the Company accounted for share-based compensation granted under its stock option plans using the recognition and measurement provisions of Accounting Principles Board Opinion No. 25, “Accounting for Stock Issued to Employees” (APB 25). Under APB 25, a company was not required to recognize compensation expense for stock options issued to employees if the exercise price of the stock options was at least equal to the quoted market price of the company’s common stock on the “measurement date.” APB 25 defined the measurement date as the first date on which both the number of shares an individual employee was entitled to receive and the option or purchase price, if any, were known.

The restatement in this Form 10-K principally reflects additional stock-based compensation expense and related tax effects under both FAS 123R, the Company’s current accounting method, and APB 25, the Company’s historical accounting method, relating to the Company’s historic stock option practices. The restatement also reflects certain other accounting adjustments, including adjustments unrelated to historic stock option practices, which are not material either individually or in the aggregate to the current or prior periods.

The principal components of the restatement are as follows:

Revised Measurement Dates. Based on all available evidence, the Company applied the methodologies described below to determine the appropriate measurement dates under both FAS 123 and APB 25 for grants in the following categories: (1) grants of approximately 80 million shares on a split-adjusted basis to Section 16 officers (“Section 16 Grants”); (2) grants of approximately 260 million shares on a split-adjusted basis to middle management and senior management employees (“Broad-Based Grants”); and (3) grants of approximately 50 million shares on a split-adjusted basis in connection with the hiring or promotion of employees (“New Hire and Promotion Grants”). As a result of this analysis, the Company has determined that, in most cases, the stated grant date was not the correct measurement date.

For the majority of Section 16 Grants, Compensation Committee approval was reflected in written actions. The WilmerHale Report concluded that the written actions were generally executed subsequent to the stated grant dates. (Under Minnesota corporate law, it is permissible to make a Written Action effective as of a date other than the date on which the last of the required signers affixes his or her signature, even if that effective date is before the last signature affixed.) Based on the available evidence, the Company has determined that the appropriate measurement date for each of these Section 16 Grants is the earlier of (a) the date on which a Form 4 (or other statement of changes in beneficial ownership) was filed with the SEC with respect to a

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particular officer’s grant or (b) the date on which the written action with respect to that grant was likely executed by a majority of the members of the Compensation Committee.

As to certain other Section 16 Grants, Compensation Committee approval occurred at a meeting or there was general Compensation Committee approval of the Section 16 Grant together with a delegation to the Chairman of the Compensation Committee to determine the final amount of stock options, grant date and exercise price for each Section 16 officer receiving options. The Company has determined, based on all available evidence, that the appropriate measurement date for these Section 16 Grants is the earlier of (a) the date on which a Form 4 (or other statement of changes in beneficial ownership) was filed with the SEC with respect to a particular officer’s grant or (b) the date on which a resolution with respect to that grant was adopted at a meeting of the Compensation Committee or a decision was made by the Chairman of the Compensation Committee, if so delegated.

For option grants with stated grant dates in October 1999 that were made in connection with the entry of employment agreements for our former chief executive officer and our current chief executive officer (both of whom had been employed by the Company prior to that date), the Company has determined that the appropriate measurement date is the date on which the employment agreements were executed on behalf of the Company. With respect to stock option grants with a stated grant date in October 1999 that represented the number of additional stock options necessary to equal the minimum annual stock option grant provided for pursuant to each such employment agreement, the Company has determined that the appropriate measurement date is the last day of 1999, the calendar year in which the Company was contractually obligated to make the grants.

The Company followed separate allocation processes to determine the particular recipients and individual option amounts of grants to middle management employees and senior management employees. In the majority of Broad-Based Grants, the process of allocating stock option grants among individual employees in both middle management and senior management continued beyond the stated grant date. After the date on which substantially all granting activities were completed, there was an insignificant number of changes to option awards attributable to circumstances such as the effective cancellation of a grant because of an employee’s termination, administrative error corrections, promotion or individual performance reassessment.

Based on all available evidence, the Company has determined that the appropriate measurement date for Broad-Based Grants was the later of the following two dates: (a) the date on which the evidence identified by the Company indicated that a communication to or from our former chief executive officer refers to a particular grant, or the grant was presented to the Compensation Committee or (b) the date on which the allocation of the options to individual employees and grant process associated with the Broad-Based Grant was substantially complete. Where information is not available to evidence either (a) or (b) above, the Company has determined the appropriate measurement date to be the date on which the Company determined, based upon all available evidence, that the CEO Certificate for such grant was likely executed. Where option award amounts changed subsequent to the date the allocation process was substantially complete, the Company has determined that each award that was changed is a separate grant with its own measurement date and should not be considered indicative that the granting process was not complete.

For New Hire and Promotion Grants made prior to 2002, the Company typically chose grant dates by determining the lowest closing price of the Company’s common stock between the date of an event in

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the recruitment of the newly hired employee (e.g., date of first contact, date of an offer letter) or promotion of the employee and the end of the quarter in which the employee started work or was promoted. As a result of this practice, some employees received stock options with grant dates that were earlier than that employee’s start date. In 2002, the Company changed to a practice of determining grant dates for new hires and promotions to be the date of the lowest closing price of the Company’s common stock between the start date of employment or date of promotion and the end of the quarter in which the employee started work or was promoted. The Company historically used these stated grant dates as the measurement dates for accounting purposes.

The Company has concluded that the measurement dates used with respect to nearly all of the New Hire and Promotion Grants during the Independent Review Period were not correct because the Company’s practice was to determine grant dates with the benefit of hindsight. The Company has determined that the appropriate measurement date for each New Hire and Promotion Grant was the date on which the Company set the terms of the award or, if the Company could not identify such date based on all available evidence, the last date of the fiscal quarter in which a particular New Hire or Promotion Grant was made.

1999 Grant of Supplemental Options. In the fourth quarter of 1999, following a decline in its stock price, the Company granted “supplemental” stock options to acquire 2.2 million shares of Company common stock (17.6 million shares on a split-adjusted basis) to a broad group of employees, including our former chief executive officer and other Section 16 officers. The supplemental options were granted in connection with the suspension of the vesting and exercisability of an equal number of options with exercise prices above $46.50 ($5.8125 on a split-adjusted basis) that had previously been granted to those employees (the “Suspended Options”). The supplemental options had a stated grant date of October 13, 1999 and an exercise price equal to $40.125 ($5.0156 on a split-adjusted basis).

After taking into account all available evidence regarding the Suspended Options, the Company has concluded that, under APB 25, the grant of the supplemental options constituted an effective re-pricing subject to variable accounting for each option until exercise, forfeiture or expiration. Additionally, the Company has determined that, under FAS 123, the grant of the supplemental options was a modification that required an incremental fair value charge to be recognized over the related vesting period.

2000 Reactivation of Suspended Options. In 2000, the Company reactivated the vesting and exercisability of the Suspended Options. The Company has determined that, under APB 25 and FAS 123, the reactivation of the vesting and exercisability of the Suspended Options was a new stock option grant that should have had a new measurement date, and the Company has determined that the appropriate measurement date is the date grantees were again permitted to exercise their previously vested awards.

Cliff Vesting Options. Prior to April 2000, the Company granted to employees certain stock options that vested 100% on the sixth or ninth anniversary of the date of grant (the “Cliff Vesting Options”). Under the terms of the options, the Company could elect to accelerate the vesting of all or a portion of the Cliff Vesting Options at its discretion. The Company followed a policy of accelerating the vesting of a consistent percentage of the Cliff Vesting Options, unless the option holder was subject to disciplinary action or performing at a less than satisfactory level. This resulted in nearly all option holders having their Cliff Vesting Options accelerated so they actually vested as if they had a 20% or 25% per year time-based vesting schedule (i.e., a four-year or five-year vesting period).

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Other Modifications of Option Terms. The Company has also determined that certain other actions were taken that resulted in the modification of option terms, as follows:

Related Tax Adjustments. The restatement in this Form 10-K also reflects the estimated loss of certain tax deductions and additional interest expense related to the exercise of stock options granted to certain of the Company’s executive officers that — as a result of the revision of measurement dates—no longer qualify as deductible performance-based compensation in accordance with Internal Revenue Code section 162(m).

Additional Information

Note 3 of the Notes to Consolidated Financial Statements in this Form 10-K sets forth, on a year-by-year basis, the impact under FAS 123R and APB 25 of recognizing additional stock-based compensation expense and related tax effects as a result of historic stock option practices.

The Company also conducted a sensitivity analysis to assess how the restatement adjustments described in this Form 10-K would have changed under two alternative methodologies for determining measurement dates for stock option grants made during the Independent Review Period. See “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” presented in Item 7 of this Form 10-K, for information regarding the incremental stock-based compensation cost that would result from using alternate measurement date determination methodologies. See “Cautionary Statements” in Item 7 for a discussion of certain risk factors related to the Company’s historic stock option practices.

Item 9A of this Form 10-K describes management’s conclusion, in light of the findings of the WilmerHale Report and the restatement reflected in this Form 10-K and as reported in a Current Report on Form 8-K filed

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with the SEC on November 8, 2006, that the Company had a material weakness in internal control over financial reporting solely relating to stock option plan administration and accounting for and disclosure of stock option grants as of December 31, 2005 and that, solely for this reason, its internal control over financial reporting and its disclosure controls and procedures were not effective as of that date. Item 9A of this Form 10-K further describes the conclusion of the Company’s Chief Executive Officer and Chief Financial Officer, based upon management’s evaluation of the effectiveness of the design and operation of the Company’s disclosure controls and procedures as of December 31, 2006, that the Company has remediated the material weakness in internal control over financial reporting relating to stock option plan administration and accounting for and disclosure of stock option grants and that the Company’s disclosure controls and procedures were effective at the reasonable assurance level as of December 31, 2006.

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PART I

INTRODUCTION

Overview

UnitedHealth Group (“we,” “our,” or “the Company”) is a diversified health and well-being company, serving approximately 70 million Americans. We are focused on improving the American health care system and how it works for multiple, distinct constituencies. We provide individuals with access to quality, cost-effective health care services and resources through more than 520,000 physicians and other care providers and 4,700 hospitals across the United States.

During 2006, we managed approximately $92 billion in aggregate health care spending on behalf of the constituents and consumers we served. Our primary focus is on improving health care systems by simplifying the administrative components of health care delivery, promoting evidence-based medicine as the standard for care, and providing relevant, actionable data that physicians, health care providers, consumers, employers and other participants in health care can use to make better, more informed decisions.

Through our diversified family of businesses, we leverage core competencies in advanced technology-based transactional capabilities; health care data, knowledge and information; and health care resource organization and care facilitation to improve access to health and well-being services, simplify the health care experience, promote quality and make health care more affordable.

Our revenues are derived from premium revenues on risk-based products; fees from management, administrative, technology and consulting services; sales of a wide variety of products and services related to the broad health and well-being industry; and investment and other income. In 2006, we conducted our business primarily through operating divisions in the following business segments:

For a discussion of our financial results by segment, see Item 7 — “Management’s Discussion and Analysis of Financial Condition and Results of Operations.”

Recent Developments

Key Business Developments

The results of PacifiCare Health Systems, Inc. (“PacifiCare”), which we acquired in December 2005 for total cash and stock consideration of approximately $8.8 billion, were included for the full year 2006. This acquisition significantly strengthened our resources by enhancing our capabilities on the Pacific Coast and in other Western states and broadening the scope of our product offerings for a host of specialized services.

On January 1, 2006, we began serving as a plan sponsor offering Medicare Part D prescription drug insurance coverage under a contract with the Centers for Medicare & Medicaid Services (CMS). As of December 31, 2006, we had enrolled approximately 5.7 million members in the Part D program, including approximately 4.5 million in the stand-alone prescription drug plans and approximately 1.2 million in Medicare Advantage plans incorporating Part D coverage.

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Senior Leadership Changes

During 2006, we made significant changes in our senior management personnel and in the structure and responsibilities of senior management positions, including the following:

Business Organization Changes

Consistent with the structural changes to the Company’s executive management, we began transitioning our operating structure into the following three new market groups in 2007:

This initial operating structure will continue to evolve as we add new executive positions and realign enterprise-wide functions to strengthen our capabilities and performance. We have not currently realigned assets or changed the way our senior executives evaluate financial performance. Therefore, until we have completed the transition of our operating structure into the new market groups, we will continue to describe and report our results of operations in our earnings releases and SEC filings (including this Form 10-K) using the four business segments described in “ — Overview” above.

Executive Compensation and Corporate Governance

In addition to the senior leadership and business organization changes, our Board of Directors implemented a number of significant changes in the areas of executive compensation (including controls over equity awards) and corporate governance. The “Compensation Discussion and Analysis” and “Corporate Governance” sections of our Definitive Proxy Statement for the Annual Meeting of Shareholders to be held on May 29, 2007 will contain a detailed description of these changes. See also Item 9A of this Form 10-K for a discussion of the remediation of our internal control over financial reporting solely relating to stock option plan administration and accounting for and disclosure of stock option grants.

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Additional Information

UnitedHealth Group Incorporated was incorporated in January 1977 in Minnesota. The terms “we,” “our” or the “Company” refer to UnitedHealth Group Incorporated and our subsidiaries. Our executive offices are located at UnitedHealth Group Center, 9900 Bren Road East, Minnetonka, Minnesota 55343; our telephone number is (952) 936-1300.

You can access our Web site at www.unitedhealthgroup.com to learn more about our Company. From that site, you can download and print copies of our annual reports to shareholders, annual reports on Form 10-K, quarterly reports on Form 10-Q, and current reports on Form 8-K, along with amendments to those reports. You can also download from our Web site our Articles of Incorporation, bylaws and corporate governance policies, including our Principles of Governance, Board of Directors Committee Charters, and Code of Business Conduct and Ethics. We make periodic reports and amendments available, free of charge, as soon as reasonably practicable after we file or furnish these reports to the Securities and Exchange Commission (SEC). We will also provide a copy of any of our corporate governance policies published on our Web site free of charge, upon request. To request a copy of any of these documents, please submit your request to: UnitedHealth Group Incorporated, 9900 Bren Road East, Minnetonka, MN 55343, Attn: Corporate Secretary.

Our transfer agent, Wells Fargo, can help you with a variety of shareholder-related services, including change of address, lost stock certificates, transfer of stock to another person and other administrative services. You can write to our transfer agent at: Wells Fargo Shareowner Services, P.O. Box 64854, St. Paul, Minnesota 55164-0854, email stocktransfer@wellsfargo.com, or telephone (800) 468-9716 or (651) 450-4064.

DESCRIPTION OF BUSINESS SEGMENTS

UNIPRISE

Uniprise delivers health care and well-being services nationwide to large national employers, individual consumers and other health care organizations through three related business units: Uniprise Strategic Solutions (USS), Definity Health and Exante Financial Services (Exante). Each business unit works with other UnitedHealth Group businesses to deliver a complementary and integrated array of services. USS delivers strategic health and well-being solutions to large national employers. Definity Health provides consumer-driven health plans and consumer activation services to employers and their employees. As of December 31, 2006, USS and Definity Health served approximately eleven million individuals. Exante delivers health-care-focused financial services for consumers, employers and providers. Uniprise also offers transactional processing services to various intermediaries and health care entities. Most Uniprise products and services are delivered through its affiliates. Uniprise provides administrative and customer care services for certain other businesses of UnitedHealth Group.

Uniprise specializes in large-volume transaction management, large-scale benefit design and innovative technology solutions that simplify complex administrative processes and promote improved health outcomes. Uniprise processes approximately 270 million medical benefit claims each year and responds to approximately 50 million service calls annually. Uniprise provides comprehensive operational services for independent health plans and third-party administrators, as well as the majority of the commercial health plan consumers served by UnitedHealthcare. Uniprise maintains Internet-based administrative and financial applications for physician inquiries and transactions, for customer-specific data analysis for employers, and for consumer access to personal health care information and services.

USS

USS provides comprehensive and customized administrative, benefits and service solutions for large employers and other organizations with more than 5,000 employees in multiple locations. USS customers generally retain the risk of financing the medical benefits of their employees and their dependents and USS provides coordination and facilitation of medical services; transaction processing; consumer and care provider services; and access to contracted networks of physicians, hospitals and other health care professionals for a fixed service fee per individual served. As of December 31, 2006, USS served approximately 405 employers, including approximately 180 of the Fortune 500 companies.

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Definity Health

Definity Health provides innovative consumer health care solutions that enable consumers to take ownership and control of their health care benefits. Definity Health’s products include high-deductible consumer-driven benefit plans coupled with health reimbursement accounts (HRAs) or health savings accounts (HSAs), and are offered on a self-funded and fully insured basis. Definity Health is a national leader in consumer-driven health benefit programs and as of December 31, 2006, its products were provided to more than 18,000 group health plans across the UnitedHealth Group enterprise, including approximately 150 employers in the large group USS self-funded market.

Exante

Exante Financial Services provides health-based financial services for consumers, employers and providers. These financial services are delivered through Exante Bank, a Utah-chartered industrial bank. These financial services include HSAs that consumers can access using a debit card. Exante’s health benefit card programs include electronic systems for verification of benefit coverage and eligibility and administration of Flexible Spending Accounts (FSAs), HRAs and HSAs. Exante also provides extensive electronic payment and statement services for health care providers and payers.

HEALTH CARE SERVICES

Our Health Care Services segment consists of our UnitedHealthcare, Ovations and AmeriChoice businesses.

UnitedHealthcare

UnitedHealthcare offers a comprehensive array of consumer-oriented health benefit plans and services for public sector, small and mid-sized employers, and individuals nationwide. UnitedHealthcare facilitates access to health care services on behalf of nearly 15 million Americans as of December 31, 2006. With its risk-based product offerings, UnitedHealthcare assumes the risk of both medical and administrative costs for its customers in return for a monthly premium, which is typically at a fixed rate for a one-year period. UnitedHealthcare also provides administrative and other management services to customers that self-insure the medical costs of their employees and their dependents, for which UnitedHealthcare receives a fixed service fee per individual served. These customers retain the risk of financing medical benefits for their employees and their dependents, while UnitedHealthcare provides coordination and facilitation of medical services, customer and care provider services and access to a contracted network of physicians, hospitals and other health care professionals. Small employer groups are more likely to purchase risk-based products because they are generally unable or unwilling to bear a greater potential liability for health care expenditures. UnitedHealthcare also offers a variety of non-employer based insurance options for purchase by individuals, which are designed to meet the health coverage needs of consumers and their families.

UnitedHealthcare offers its products through affiliates that are usually licensed as insurance companies or as health maintenance organizations, depending upon a variety of factors, including state regulations. UnitedHealthcare’s product strategy centers on several principles: consumer choice, broad access to health professionals, use of data and science to promote better outcomes, quality service and greater affordability. Integrated wellness programs and services help individuals make informed decisions, maintain a healthy lifestyle and optimize health outcomes by coordinating access to care services and providing personalized, targeted education and information services.

UnitedHealthcare arranges for discounted access to care through more than 520,000 physicians and other care providers, and 4,700 hospitals across the United States. The consolidated purchasing capacity represented by the individuals UnitedHealth Group serves makes it possible for UnitedHealthcare to contract for cost-effective access to a large number of conveniently located care providers. Directly or through UnitedHealth Group’s family of companies, UnitedHealthcare offers:

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UnitedHealthcare’s regional and national access to broad, affordable and quality networks of health care providers has advanced over the past three years, with significant increases in access to services in California, Connecticut, Delaware, Florida, Central Illinois, Northern Indiana, Iowa, Maryland, Massachusetts, Western Michigan, Nevada, New Hampshire, New Jersey, New York, Oregon, Pennsylvania, Eastern Tennessee, Virginia, Washington, West Virginia, Wisconsin, and Washington DC. UnitedHealthcare has also organized health care alliances with select regional not-for-profit health plans to facilitate greater customer access and affordability.

We believe that UnitedHealthcare’s innovation distinguishes its product offerings from the competition. Its consumer-oriented health benefits and services value individual choice and control in accessing health care. UnitedHealthcare has programs that provide health education, admission counseling before hospital stays, care advocacy to help avoid delays in patients’ stays in the hospital, support for individuals at risk of needing intensive treatment and coordination of care for people with chronic conditions. Data-driven networks and clinical management are organized around clinical lines of service such as behavioral health; cardiology; congenital heart disease; kidney disease; oncology; neuroscience; orthopedics; spine; women’s health; primary care and transplantation to provide consumers with the necessary resources and information to make more informed choices when managing their health. UnitedHealthcare also offers comprehensive and integrated pharmaceutical management services that achieve lower costs by using formulary programs that drive better unit costs for drugs, benefit designs that encourage consumers to use drugs that offer the best value and outcomes, and physician and consumer programs that support the appropriate use of drugs based on clinical evidence.

UnitedHealthcare’s distribution system consists primarily of insurance producers and direct and Internet marketing sales in the individual market; insurance producers in the small employer group market; and producers and other consultant-based or direct sales for large employer and public sector groups. UnitedHealthcare’s direct distribution efforts are generally limited to the individual market, portions of the large employer group and public sector markets, and cross-selling of specialty products to existing customers.

Ovations

Ovations provides health and well-being services for individuals age 50 and older, addressing their unique needs for preventive and acute health care services as well as for services dealing with chronic disease and other specialized issues for older individuals. Ovations, through its affiliates, is one of few enterprises fully dedicated to this market segment, providing products and services in all 50 states, the District of Columbia, Puerto Rico, the U.S. Virgin Islands, Guam and the Northern Mariana Islands. Ovations participates nationally in the Medicare program, offering a wide-ranging spectrum of Medicare products, including Medigap products that

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supplement traditional fee-for-service coverage, more traditional health-plan-type programs under Medicare Advantage, Medicare Part D prescription drug coverage and discount card offerings, and special offerings for chronically ill and Medicare and Medicaid dual-eligible beneficiaries.

Ovations has extensive capabilities and experience with distribution, including direct marketing to consumers on behalf of its key clients — AARP, the nation’s largest membership organization dedicated to the needs of people age 50 and over, state and U.S. government agencies and employer groups. Ovations also has distinct pricing, underwriting and clinical program management, and marketing capabilities dedicated to risk-based health products and services in the senior and geriatric markets.

CMS is overseeing a multi-year implementation of the 2003 Medicare Modernization Act, including the introduction of the Medicare Part D prescription drug benefit in 2006 and a greater diversity in Medicare’s product offerings. We believe that these changes create and expand opportunities for well-organized and focused companies to better serve older Americans. We believe that Ovations is well-positioned to respond to these opportunities.

We currently have a number of contracts with CMS, which primarily relate to the Medicare health benefit program authorized under the Medicare Modernization Act. Beginning January 1, 2006, we began serving as a plan sponsor offering Medicare Part D prescription drug insurance coverage. As a result of this contract and the December 2005 acquisition of PacifiCare, premium revenues from CMS approximated 26% of our total consolidated revenues as of December 31, 2006, a majority of which were generated by Ovations.

Insurance Solutions

Ovations offers a range of health insurance products and services to AARP members, and has expanded the scope of services and programs offered over the past several years. Ovations provides Medicare Supplement and hospital indemnity insurance from its insurance company affiliates to approximately 3.8 million AARP members. Additional Ovations services include a nurse healthline service, a lower cost Medicare Supplement offering that provides consumers with a hospital network and 24-hour access to health care information. Ovations also offers an AARP-branded health insurance program focused on persons between 50 and 64 years of age.

Medicare Prescription Drug Benefit (Part D)

Effective January 1, 2006, Ovations provides the Medicare prescription drug benefit (Part D) to beneficiaries throughout the United States and its territories. Among the several Part D plans it offers, Ovations provides a Medicare prescription drug coverage plan branded by AARP. Ovations also provides Part D drug coverage through its Medicare Advantage program, Special Needs Plans and stand-alone prescription drug plans. As of December 31, 2006, including PacifiCare, Ovations had enrolled approximately 5.7 million members in the Part D program, including approximately 4.5 million in the stand-alone prescription drug plans and approximately 1.2 million in Medicare Advantage plans incorporating Part D coverage.

Secure Horizons

The Ovations Secure Horizons division provides health care coverage for the seniors market primarily through the Medicare Advantage program administered by CMS. Ovations offers Medicare Advantage HMO, preferred provider organization (PPO), Special Needs Plans and Private-Fee-for-Service plans. Under the Medicare Advantage programs, Ovations provides health insurance coverage to eligible Medicare beneficiaries in exchange for a fixed monthly premium per member from CMS that varies based on the geographic areas in which members reside. Most products are offered under the “Secure Horizons by UnitedHealthcare” brand name. In 2006, Ovations’ Secure Horizons expanded its program and now offers Medicare Advantage products in all 50 states. As of December 31, 2006, Ovations had approximately 1.4 million enrolled individuals in its Medicare Advantage products, of whom more than 1.2 million will receive their Part D coverage through Secure Horizons. Ovations began offering a regional PPO Medicare Advantage plan in three markets on January 1, 2006.

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Evercare

Through its Evercare division, Ovations is one of the nation’s leaders in offering complete, individualized care planning and care benefits for aging, disabled and chronically ill individuals. Evercare serves approximately 124,000 people (including 53,000 with Medicare Advantage) across the nation in long-term care settings including nursing homes, community-based settings and private homes, as well as through hospice and palliative care. Evercare offers services through innovative care management and clinical programs.

Evercare integrates federal, state and private funding through a continuum of products from Special Needs Plans and long-term care Medicaid programs to hospice care, and serves people in 35 markets in home, community and nursing home settings. These services are provided primarily through nurse practitioners, nurses and care managers. Evercare operated Special Needs Plans in 34 states as of December 31, 2006.

Evercare Solutions for Caregivers is a comprehensive eldercare service program providing service coordination, consultation, claim management and information resources nationwide. Proprietary, automated medical record software enables the Evercare clinical care teams to capture and track patient data and clinical encounters, creating a comprehensive set of coherent care information that bridges across home, hospital and nursing home care settings for high-risk populations. Evercare also operates hospice and palliative care programs in nine states and intends to expand these products into at least five new markets in 2007.

Prescription Solutions^®

Prescription Solutions offers integrated pharmacy benefit management (PBM) services (including mail order pharmacy services) to approximately 6.6 million people, as of December 31, 2006. Prescription Solutions offers a broad range of innovative programs, products and services designed to enhance clinical outcomes with appropriate financial results for employers and members. The fulfillment capabilities of Prescription Solutions are an important strategic component in serving PacifiCare’s legacy commercial and senior business, as well as PacifiCare’s Part D enrollees. Effective January 1, 2007, Prescription Solutions began providing PBM services to an additional four million Ovations Medicare Advantage and stand-alone Part D members.

AmeriChoice

AmeriChoice, through its affiliates, provides network-based health and well-being services to beneficiaries of state Medicaid, Children’s Health Insurance Programs (CHIP), and other government-sponsored health care programs. AmeriChoice provides health insurance coverage to eligible Medicaid beneficiaries in exchange for a fixed monthly premium per member from the applicable state. AmeriChoice provides services to approximately 1.4 million individuals in 13 states. AmeriChoice also offers government agencies a broad menu of separate management services — including clinical care, consulting and management, pharmacy benefit services and administrative and technology services — to help them effectively administer their distinct health care delivery systems and benefits for individuals in their programs. AmeriChoice also contracts with CMS for the provision of Special Needs Plans serving individuals dually eligible for Medicaid and Medicare services. These programs are primarily organized toward enrolling individuals who dually qualify for Medicaid and Medicare coverage in states where AmeriChoice operates its Medicaid health plans.

AmeriChoice’s approach is grounded in its belief that health care cannot be provided effectively without considering all of the factors — social, economic, environmental, and physical — that affect a person’s life. AmeriChoice coordinates resources among family members, physicians, other health care providers and government and community-based agencies and organizations to provide continuous and effective care. For members, this means that the AmeriChoice Personal Care Model offers them a holistic approach to health care, emphasizing practical programs to improve their living circumstances as well as quality medical care and treatment in accessible, culturally sensitive, community-oriented settings. For example, AmeriChoice’s disease management and outreach programs focus on high-prevalence and debilitating illnesses such as hypertension and

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cardiovascular disease, asthma, sickle cell disease, diabetes, Human Immunodeficiency Virus/Acquired Immune Deficiency Syndrome (HIV/AIDS), cancer and high-risk pregnancy. Several of these programs have been developed by AmeriChoice with the help of leading researchers and clinicians at academic medical centers and medical schools.

For physicians, the AmeriChoice Personal Care Model means assistance with coordination of their patients’ care. AmeriChoice utilizes sophisticated technology to monitor preventive care interventions and evidence-based treatment protocols to support care management. AmeriChoice utilizes advanced and unique pharmacy services — including benefit design, generic drug programs, drug utilization review and preferred drug list development — to help optimize the use of appropriate quality pharmaceuticals and concurrently manage pharmacy expenditures to levels appropriate to the specific clinical situations. For state customers, the AmeriChoice Personal Care Model means increased access to care and improved quality for their beneficiaries, in a measurable system that reduces their administrative burden and lowers their costs.

AmeriChoice considers a variety of factors in determining in which state programs to participate and on what basis, including the state’s experience and consistency of support for its Medicaid program in terms of service innovation and funding, the population base in the state, the willingness of the physician/provider community to participate with the AmeriChoice Personal Care Model, and the presence of community-based organizations that can partner with AmeriChoice to meet the needs of its members. Using these criteria, AmeriChoice entered three new markets in 2006, signed an agreement to expand in one existing market in 2007, and is examining several others. Conversely, in recent years, AmeriChoice has exited several markets because of, among other reasons, the lack of consistent direction and support from the sponsoring states.

SPECIALIZED CARE SERVICES

The Specialized Care Services (SCS) companies offer a comprehensive platform of specialty health and wellness and ancillary benefits, services and resources to specific customer markets nationwide. These products and services include employee benefit offerings, provider networks and related resources focusing on behavioral health and substance abuse, dental, vision, disease management, complex and chronic illness and care facilitation. The SCS companies also offer solutions in the areas of complementary and alternative care, employee assistance, short-term disability, life insurance, work/life balance and health-related information. These services are designed to simplify the consumer health care experience and facilitate efficient health care delivery.

SCS’s products are marketed under several different brands through three strategic markets we serve: the employer market for both UnitedHealth Group customers and unaffiliated parties; the payer market for UnitedHealth Group health plans, independent health plans, third-party administrators and reinsurers; and the public sector segment for Medicare and state Medicaid offerings through partnerships with Ovations, AmeriChoice and other intermediaries. SCS offers its products both on an administrative fee basis, where it manages and administers benefit claims for self-insured customers in exchange for a fixed service fee per individual served, and on a risk basis, where SCS assumes responsibility for health care and income replacement costs in exchange for a fixed monthly premium per individual served. The simple, modular service designs offered by SCS can be easily integrated to meet varying health plan, employer and consumer needs at a wide range of price points. Approximately 53% of the 56 million unique consumers served by SCS receive their major medical health benefits from a source other than a UnitedHealth Group affiliate.

For most of 2006, SCS consisted of three operating groups: Specialized Health Solutions; Dental and Vision; and Group Insurance Services. In December 2006, Group Insurance Services and Dental and Vision were combined into the Group Benefits Solutions operating group.

Specialized Health Solutions

The Specialized Health Solutions operating group provides services and products for benefits commonly found in comprehensive medical benefit plans, as well as a continuum of individualized specialty health and wellness

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solutions from health information to case and disease management for complex, chronic and rare medical conditions.

United Behavioral Health (UBH) and its subsidiaries provide employee assistance programs, work/life, behavioral health care, substance abuse programs and psychiatric disability benefit management services to employers, health plans, labor groups and public payers. UBH’s programs assist individuals in managing personal challenges and behavioral health issues while seeking to increase overall health, wellness and productivity. UBH’s customers buy care management services and access to UBH’s large national network of 78,000 clinicians and counselors through standard and highly customized behavioral programs. UBH serves 33 million individuals.

ACN Group (ACN) and its affiliates provide benefit administration, and clinical and network management for chiropractic, physical therapy, occupational therapy and other complementary and alternative care services. ACN serves more than 24 million consumers through its national network of contracted health professionals.

Through Optum, SCS delivers personalized care and condition management, health assessments, longitudinal care management, disease management, health information assistance, support and related services including wellness services. Utilizing evidence-based medicine, technology and specially trained nurses, Optum facilitates effective and efficient health care delivery by helping its 32 million consumers address daily living concerns, make informed health care decisions, and become more effective health care consumers.

United Resource Networks (URN) provides support services and access to “Centers of Excellence” networks for individuals in need of organ transplantation and those diagnosed with complex cancer, congenital heart disease, kidney disease, infertility and neonatal care issues. URN provides these services to approximately 50 million individuals through 2,800 payers. URN negotiates competitive rates with medical centers that have been designated as “Centers of Excellence” based on their satisfaction of clinical standards, including patient volumes and outcomes, medical team credentials and experience, and patient and family support services.

Group Benefits Solutions

Group Benefits Solutions provides vision, dental, life, critical illness, and short-term disability benefits along with cost management products and services for governments, health plans and employers through its affiliates and other intermediaries.

Spectera provides vision benefits for more than eleven million people enrolled in employer-sponsored and government benefit plans. Spectera works to build productive relationships with vision care professionals, retailers, employer groups and benefit consultants. Spectera’s national network includes more than 24,000 vision professionals.

Through UnitedHealthcare Dental and other brands (UHD), we provide dental benefit management and related services to six million individuals through a network of approximately 80,000 dentists. UHD’s products are distributed to commercial and government markets, both directly and through unaffiliated insurers and its UnitedHealth Group affiliates.

Unimerica Workplace Benefits provides integrated short-term disability, critical illness and group life insurance products to employer’s benefit programs.

National Benefit Resources (NBR) distributes and administers medical stop-loss insurance covering self-funded employer benefit plans. Through a network of third-party administrators, brokers and consultants, NBR markets stop-loss insurance throughout the United States. NBR also distributes products and services on behalf of its SCS affiliates, URN and Optum.

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INGENIX

Ingenix offers database and data management services, software products, publications, consulting services, outsourced services and pharmaceutical development and consulting services on a nationwide and international basis. Ingenix’s customers include more than 5,000 hospitals, 250,000 physicians, 1,500 payers and intermediaries, more than 200 Fortune 500 companies, and more than 150 life sciences companies, as well as other UnitedHealth Group businesses. Ingenix is engaged in the simplification of health care administration with information and technology that helps customers accurately and efficiently document, code and bill for the delivery of care services. Ingenix is a leader in contract research services, medical education services, publications, and pharmacoeconomics, outcomes, safety and epidemiology research through its i3 businesses.

Ingenix’s products and services are sold primarily through a direct sales force focused on specific customers and market segments across the pharmaceutical, biotechnology, employer, government, hospital, physician and payer market segments. Ingenix’s products are also supported and distributed through an array of alliance and business partnerships with other technology vendors, who integrate and interface its products with their applications.

The Ingenix companies are divided into two operating groups: information services and pharmaceutical services.

Information Services

Ingenix’s diverse product offerings help clients strengthen health care administration and advance health care outcomes. These products include health care utilization reporting and analytics, physician clinical performance benchmarking, clinical data warehousing, analysis and management responses for medical cost trend management, decision-support portals for evaluation of health benefits and treatment options, and claims management tools for administrative error and cost reduction. Ingenix uses proprietary software applications that manage clinical and administrative data across diverse information technology environments. Ingenix also uses proprietary predictive algorithmic applications to help clients detect and act on repetitive health care patterns in large data sets. Ingenix offers complete Electronic Data Interchange (EDI) services helping health care providers and payers decrease costs of claims transmission, payment and reimbursement through both networked and direct connection services.

Ingenix provides other services on an outsourced basis, such as verification of physician credentials, provider directories, HEDIS reporting, and fraud and abuse detection and prevention services. Ingenix also offers consulting services, including actuarial and financial advisory work through its Reden & Anders division, as well as product development, provider contracting and medical policy management. Ingenix publishes print and electronic media products that provide customers with information regarding medical claims coding, reimbursement, billing and compliance issues.

Pharmaceutical Services

Ingenix’s i3 division helps to coordinate and manage clinical trials for products in development for pharmaceutical, biotechnology and medical device manufacturers. Ingenix’s focus is to help pharmaceutical and biotechnology customers effectively and efficiently get drug and medical device data to appropriate regulatory bodies and to improve health outcomes through integrated information, analysis and technology. Ingenix’s capabilities and efforts focus on the entire range of product assessment, through commercialization of life-cycle management services — pipeline assessment, market access and product positioning, clinical trials, economic, epidemiology, safety and outcomes research, and medical education. Ingenix’s services include global contract research services, protocol development, investigator identification and training, regulatory assistance, project management, data management, biostatistical analysis, quality assurance, medical writing and staffing resource services. Ingenix’s pharmaceutical contract research operations are in more than 50 countries and are therapeutically focused on oncology, the central nervous system, respiratory and infectious diseases, and endocrinology. Ingenix uses comprehensive, science-based evaluation and analysis and benchmarking services to support pharmaceutical, biotechnology and medical device development. Ingenix also helps educate providers about pharmaceutical products through medical symposia, product communications and scientific publications.

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GOVERNMENT REGULATION

Most of our health and well-being services are regulated by federal and state regulatory agencies that generally have discretion to issue regulations and interpret and enforce laws and rules. This regulation can vary significantly from jurisdiction to jurisdiction. Changes in applicable laws and regulations are continually being considered, and the interpretation of existing laws and rules also may change periodically. Complying with new laws and rules, or changes in the interpretation of existing laws and rules, could negatively impact our business. We believe we are in compliance in all material respects with the applicable laws, rules and regulations.

Federal Regulation

We are subject to federal regulation. Ovations’ Medicare business and AmeriChoice’s Medicaid business are regulated by CMS. CMS has the right to audit performance to determine compliance with CMS contracts and regulations and the quality of care being given to Medicare beneficiaries. Our Health Care Services segment, through AmeriChoice, also has Medicaid and State Children’s Health Insurance Program contracts that are subject to federal and state regulations regarding services to be provided to Medicaid enrollees, payment for those services, and other aspects of these programs. There are many regulations surrounding Medicare and Medicaid compliance. In addition, the portion of Ingenix’s business that includes clinical research is subject to regulation by the U.S. Food and Drug Administration.

State Regulation

AmeriChoice is subject to regulation by state Medicaid agencies that oversee the provision of benefits by AmeriChoice to its beneficiaries. In addition, all of the states in which our subsidiaries offer insurance and health maintenance organization products regulate those products and operations. These states require periodic financial reports and establish minimum capital or restricted cash reserve requirements. Health plans and insurance companies are regulated under state insurance holding company regulations. Such regulations generally require registration with applicable state Departments of Insurance and the filing of reports that describe capital structure, ownership, financial condition, certain intercompany transactions and general business operations. Some state insurance holding company laws and regulations require prior regulatory approval of acquisitions and material intercompany transfers of assets, as well as transactions between the regulated companies and their parent holding companies or affiliates. These laws may restrict the ability of our regulated subsidiaries to pay dividends. In addition, some of our business and related activities may be subject to PPO, managed care organization (MCO), utilization review (UR) or third-party administrator-related regulations and licensure requirements. These regulations differ from state to state, but may contain network, contracting, product and rate, financial and reporting requirements. There are laws and regulations that set specific standards for delivery of services, payment of claims, fraud prevention, protection of consumer health information and covered benefits and services. Our pharmacy activities are generally regulated at the state level and may require registration or licensure with certain state boards of pharmacy. Additionally, different approaches to state and federal privacy and insurance regulation and varying enforcement philosophies in the different states may adversely affect our ability to standardize our products and services across state lines.

In connection with the PacifiCare acquisition, which closed on December 20, 2005, as typically occurs in connection with a transaction of this size, certain of our subsidiaries entered into various commitments with stat